A spring and strut module typically includes a strut and a spring unit between the brake and knuckle module of the wheel assembly and the frame of the vehicle. The strut incorporates a shock absorber which has a piston reciprocable in a cylinder. The piston has a rod secured to a strut mount which is bolted to the frame of the vehicle. The spring unit includes a spring which resists retraction of the piston. The spring is compressed between a lower spring seat secured to the cylinder of the shock absorber and an upper spring seat. A bearing is positioned between the upper spring seat and the strut mount. This invention is directed to the upper spring seat and bearing assembly.
According to prior technology, the upper spring seat was a stamped steel part over-molded with rubber, with a glued in bearing. A sealing system to keep dirt away from the bearing included a labyrinth seal between the upper spring seat and the strut mount. If there was slight misalignment between the strut mount and upper spring seat, the strut mount would rub on the rubber overcoating the upper spring seat, causing a squeaking noise, which was highly objectionable to the operator of the vehicle. The rubber would not wear away readily, so that the squeaking persisted. Also, the misaligned parts would open the labyrinth, allowing dirt to enter the bearing, resulting in premature bearing failure.
Both of these concerns, namely, noise and early bearing failure, can be attributed, at least in part, to the labyrinth system. Therefore a need exists to improve the dimensionals of the system and utilize a labyrinth in which, even when rubbing occurs, no discernable noise results or at least does not persist. In accordance with this invention, the upper spring seat is made of a plastic material, preferably a glass fiber reinforced Nylon. Therefore, if rubbing occurs, the plastic of the upper seat will simply wear away perhaps causing noise for a short time but due to the wear the noise will disappear.
Further improvement in the system involves a reduction in the number of parts required in the bearing. The races of the bearing are held between a bearing cap and a bearing base. In accordance with the invention, the bearing base, rather than being a separate part, is made as an integral part of the upper spring seat. By incorporating the bearing base into the upper spring seat, the number of parts is reduced and the accuracy of the assembly is improved so that misalignment is reduced if not eliminated altogether, and rubbing of the upper spring seat on the strut mount does not occur. The bearing base and bearing cap are designed to provide a further labyrinth protecting the bearing from the intrusion of foreign matter.
One object of this invention is to provide a bearing and upper spring seat assembly for a spring and strut mount of an automotive vehicle having the foregoing features and capabilities.
Another object of the invention is to provide a bearing and upper spring seat assembly which is composed of a relatively few simple parts, is rugged and durable in use, and is capable of being easily and inexpensively manufactured and assembled.
These and other objects, features and advantages of the invention will become more apparent as the following description proceeds, especially when considered with the accompanying drawings.